It started with a quiet day, and a curious bag of sand brought into the extension office but inside was more than just sand. It was crawling with tawny crazy ants (Nylanderia fulva), one of Florida’s fastest-spreading invasive pests. Known for their erratic movement and massive colonies that can make the ground seem alive, these reddish-brown ants are now a growing concern for gardeners across some Florida counties. Unlike fire ants, tawny crazy ants don’t sting, but they can nip with their chewing mouthparts. Their sheer numbers can overwhelm outdoor spaces, crawling on people and spoiling the enjoyment of patios, gardens, and recreational areas. They nest in moist, protected areas such as leaf litter, potted plants, and under debris, often forming sprawling colonies with multiple queens.
Beyond being a nuisance, these ants pose serious risks. They’ve been known to cause electrical shortages by infiltrating equipment, sometimes leading to costly damage. In some Caribbean islands, they’ve harmed organic crops, and in Colombia, infestations have even led to the death of small animals due to asphyxiation. Larger animals have been attacked around sensitive areas like the eyes and hooves. Tawny crazy ants also disrupt local ecosystems. Their aggressive spread displaces native ant species and reduces biodiversity. While Florida hasn’t reported agricultural damage yet, the potential remains, especially in organic farming systems.
Identification Tips
Workers are small (less than 1/8 inch), monomorphic, and covered in fine hairs that give them a matte appearance. They have one petiole segment and 12 antennal segments, including a long first segment called the scape. Colonies don’t form mounds but may tunnel in sandy soil. Queens are often found among workers, especially in warmer months. If you suspect an infestation, contact your local UF/IFAS Extension office.
Management Challenges
Controlling tawny crazy ants is notoriously difficult. Spraying alone is ineffective, and most insecticides only work for a few days before ants’ return. Integrated Pest Management (IPM) is the recommended approach. IPM combines multiple tactics, starting with accurate identification and monitoring, followed by strategic product application and habitat modification. Professional pest control services that specialize in IPM are often necessary. Timing is critical, and overuse of products is not only ineffective but may violate legal limits. Keep records of infestation locations to anticipate reinvasion, which typically occurs annually. While complete eradication is unlikely in established areas, population suppression is achievable. Interestingly, research suggests that within about a decade, populations may naturally decline, allowing native species to rebound.
Tawny crazy ants are more than just a backyard annoyance they are a complex ecological and household threat. Awareness, early identification, and professional management are key to minimizing their impact. As these ants continue to spread, staying informed and proactive will help protect your property and Florida’s delicate ecosystems.
For more information call or visit your local extension office or follow the link below.
Doodlebugs create pitfall traps in dry, sandy areas to lure unsuspecting ants. Their “doodles” in the sand are visible as well. Photo credit: Carrie Stevenson, UF IFAS Extension
It’s been years since I ran across doodlebugs. But when I saw a stretch of their pitfall traps at a campsite near Coldwater Creek in MIlton, I knew it was time to write about them. Lore says their silly name came from Southern kids like me, who watched the larvae drag their bodies around in the sand, leaving patterns (or doodles) etched behind them. These insects have long fascinated children and creative writers, with some of my favorite authors–Twain, Steinbeck, Thoreau–referencing doodlebugs in their books.
Doodlebug larvae are pretty terrifying, with those giant killer mandibles. Photo credit: UF IFAS
Doodlebugs, aka ant lions (Myrmeleon immaculatus—although we have 22 species in Florida!), are fascinating little insects that prey upon ants by creating slippery funnels in the sand. They wait underground below the funnel opening as unsuspecting ants march along the surface and slide down in the ensuing “mini avalanche.” If an ant or other prey item manages to get away, the ant lion can sling sand at it to try and knock it back down into the pit. Doodlebug larvae are the stuff of cartoon nightmares. They possess a pair of giant clawed mandibles, capable of grabbing and injecting prey with a toxin. The poison paralyzes the victim and contains digestive fluids which liquify its insides. At this point, the ant lion goes in for the kill by sucking out the prey’s juices through its deadly mandibles.
An adult doodlebug/ant lion bears no resemblance to its larval stage! Photo credit: Campbell Vaughn, UGA
Ant lions may stay in this frightening larval stage for up to 3 years. After this they undergo metamorphosis, spending 3 weeks in a cocoon. As adults, their transformation is dramatic; they are closely related to lacewings and dobsonflies, with long, thin bodies and large translucent wings.
A doodlebug captures its prey. Photo credit: UF IFAS
As kids, we always found doodlebugs under my best friend’s treehouse. In Milton, they were in a sandy area beneath a cabin roof overhang. These dry, protected sand areas are their preferred habitat and the best place to find them. We used to stick pine needles down into the openings, and watch as a flutter of insect mouthparts tried to grab it from us. Because of their fascinating life cycle and dramatic hunting technique, doodlebugs can be a captivating addition to a science classroom. In fact, there’s a reference to doodlebugs on the NASA website, due to an Apollo 16 astronaut’s mention of them. When landing on the moon, the craters reminded Charlie Duke of doodlebug pits, prompting him to recite an old children’s rhyme, “Doodlebug, doodlebug, are you at home?”
In Florida, we have plenty of native critters trying to find their way into our homes – cockroaches, mosquitoes, lizards, squirrels, mice, and even alligators and bears every now and again. So, we don’t really need any more non-native critters to worry about, but we do. The Argentine ant is one of these non-native nuisances that can be quite difficult to control.
The Argentine ant is from South America and has become a pest worldwide. Although these ants don’t sting or bite, they can be a major nuisance in the home as they search for food and water. A unique feature that makes these ants especially difficult to deal with is that they form multi-queen colonies that can form a network of interrelated colonies. Unlike other ant colonies that may compete with each other, Argentine ants are able to spend less time defending their nests and more time looking for resources. These ants are also really small, with the workers only about 2.2 to 2.6 mm (around 1/10 of an inch). The Argentine ant emits a musky odor when crushed, helping to identify it among other small pest ants.
The Argentine ant is a small, nuisance pest ant that readily invades structures, especially during the warmer months. Credit: April Noble, from www.antweb.com.
These minute, cooperative ants can quickly invade a structure looking for food and water, especially when it warms up. At 70°F, it takes 25 days for the pupa to change into an adult compared to only 8 days at 86°F. This ability to reproduce quickly is a trait shared by most invasive species, whether plant or animal.
While not a health threat to humans, they are very annoying pest. In the home, they are attracted to sugars and oils and like to hide in the soil of potted houseplants. Outdoors, they nest in mulch, leaves, and rotting logs. You can often find them “tending” to insects on your outdoor landscape plants. The ants eat the sugary feces of sap-feeding insects, called honeydew, and provide these insects protection in exchange. In citrus groves, the Argentine ant has been known to help the Asian citrus psyllid better compete against predators, allowing this other invasive species to potentially spread citrus greening.
This Argentine ant is “tending” a scale insect. Credit: Alex Wild, University of Texas at Austin, alexanderwild.com
To help control the Argentine ant, you need to start with the perimeter of the home. It’s best to keep a 2’ barrier around the home free of leaves, mulch, woody debris, and landscape plants. This minimizes areas to nest near the home. If they begin to enter the home, place ant bait stations or gel baits along their trail. Argentine ants tend to like sweet baits. Broadcast pesticide spray treatments are not as effective because the nest is usually located far enough below ground where the pesticides can’t penetrate. Pesticide powder formulations are available to treat small crevices. These ants are difficult to control and you may want to consider hiring a professional pest management company for backup. For more information on the Argentine ant, it’s identification and control methods, please see the UF/IFAS Argentine Ant Factsheet. For any questions on ants or other structural pests, contact your local county extension office.
